Metropolitan Bank v. Connecticut Mutual Life Insurance Company was a case heard by the United States Supreme Court in 1891. The case involved a dispute between the Metropolitan Bank and the Connecticut Mutual Life Insurance Company over a loan that the bank had made to the insurance company. The bank had loaned the insurance company $50,000, and the insurance company had agreed to pay the loan back with interest. However, the insurance company failed to make the payments, and the bank sued for the money. The Supreme Court ruled in favor of the bank, finding that the insurance company had breached its contract with the bank and was liable for the money. The Court held that the insurance company was liable for the full amount of the loan, plus interest, and that the bank was entitled to recover its costs and attorney's fees. The Court also held that the insurance company was not entitled to any set-off or counterclaims against the bank. In its decision, the Supreme Court established the principle that a party who breaches a contract is liable for the full amount of the contract, plus interest and costs. This case is still cited today as an example of the principle of contract law that a party who breaches a contract is liable for the full amount of the contract, plus interest and costs.

In Metropolitan Bank v. Connecticut Mutual Life Insurance Company, the Supreme Court was tasked with determining whether a bank had the right to set off funds from an account belonging to one of its customers against a debt owed by another customer who shared ownership in both accounts. The majority opinion held that the bank did have this right and could exercise it without first obtaining permission from either customer or any court order. Justice Field dissented on behalf of himself and two other justices, arguing that such action would be contrary to established principles of equity as well as state law which required prior notice before setting off funds between joint owners' accounts. He argued further that allowing banks to unilaterally take such actions would create uncertainty for creditors and depositors alike, leading them into dangerous financial situations where they might not be able to recover their money if something went wrong with the transaction.